1. Field of the Invention
The invention is related to an automatic abnormal behavior detection system that regards the detection problem as a two-category classification problem based on multiple features. More particularly, the invention can be applied to abnormal traffic event detection with image analysis techniques.
2. Description of Related Art
Abnormal behavior refers to unusual or statistically rare behavior. The purpose of abnormal behavior detection is to find out whether any subject, has behaved in a manner that suggests abnormality. For example, a pedestrian or a vehicle violates the traffic regulation. Abnormal behavior detection is one of the sub-topics of automatic video information searching and content analysis. Main applications of abnormal behavior detection including, extraordinary intrusion detection, safety watching of home elders, security monitoring of neighborhood alleys, etc.
In conventional systems, the detection of abnormal behavior usually identifies a specific abnormal behavior just based on a single feature. For example, in extraordinary intrusion detection, motion information is extracted from the video and used to be reference for determining whether an object's movement complies with the normal trajectory. If the detected trajectory deviates from the normal one, the associated behavior is identified as an abnormal behavior. However, in reality, the abnormal behavior or any violation instance always needs more than one description of a feature to verify the presence of the associated violated behavior. Therefore, collection of some meaningful features can be used to enhance the detection of abnormal behavior and broaden its applications.
Abnormal behavior detection has a wide range of applications. In the field of traffic regulation, an abnormal behavior is regarded as traffic violation event. Therefore, abnormal behavior detection is reasonably applicable to traffic violation detection. Currently, red light running events are detected by the underground inductive loops in the roadway which are connected with traffic signals. When a vehicle passes through an intersection under the region of surveillance during the red light phase of the traffic signals, the capture equipment, such as a camera or a recorder, can be triggered to capture the violation evidence as the vehicle passing through. However, the conventional detection scheme requires high costs in time and money for construction and maintenance due to the costs of installing and maintaining for the underground inductive loops.